缩节胺运筹对夏直播棉熟相的影响

Effects of DPC application on maturity phase in summer direct seeded cotton

为明确缩节胺运筹对夏直播棉熟相形成的影响,2018-2019年于扬州大学实验农场以中棉425为材料,设缩节胺用量0、180、360 g·hm^(-2)3个水平,施用时期分别设盛蕾期+初花期(施用比例1∶2)、盛蕾+初花期+盛花期(施用比例1∶2∶3) 2个运筹方式,同时设常规施用方式(初花期,缩节胺120 g·hm^(-2))为对照,探讨缩节胺施用量和施用时期处理对此种植方式下熟相的调节。结果表明:缩节胺用量180 g·hm^(-2)并于盛蕾期+初花期或盛蕾+初花期+盛花期使用后再通过脱叶催熟吐絮率均能达到90%以上,且吐絮强度高,较对照显著提高46.6%~71.4%。进一步回归分析表明,黄叶率保持在9.0%~12.8%之间,主茎红茎比为52.8%~53.1%,倒1果枝红茎比为28.3%~34.3%,倒2果枝红茎比为27.5%~39.8%,倒3果枝红茎比为34.3%~8.5%,倒4果枝红茎比为49.1%~51.5%,吐絮倒序位为7.1~8.1台最有利于集中吐絮。因此,缩节胺合理运筹能形成集中吐絮的熟相,为实现机采提供技术支撑。

In order to clarify the effects of dimethyl-piperidinium chloride(DPC) operation on the ripening phase of wheat post direct-seeding cotton in the Yangtze River basin, the application amount and application period of DPC were designed in Yangzhou university experimental farm from 2018 to 2019. The CCRI 425 were used as the experimental materials. Three levels of DPC amounts were set: 0、180、360 g·hm^(-2). Two levels of DPC operation were set: DPC applied at full square and early flowering stage(the ratio of dosage was 1∶2) or at full square, early flowering and peak flowering stage(the ratio of dosage was 1∶2∶3). Production application(120 g·hm^(-2)DPC applied at early flowering) was used as CK. The results showed that under the conditions of 180 g·hm^(-2)DPC applied at full square and early flowering stage(the ratio of dosage was 1∶2) or at full square, early flowering and peak flowering stage(the ratio of dosage was 1∶2∶3), the intensity of flocculation was 59%-85.3% higher than that of the control. Regression analysis further showed that the yellow leaves was 9.0%-12.8%, the ratio of red stem for main stem was 52.8%-53.1%, the ratio of red stem for first fruit branch from the terminal was 28.3%-34.3%, the ratio for second fruit branch from the terminal was 27.5%-39.8%, the ratio of red stem for third fruit branch from the terminal was 34.3%-48.5%, the ratio of red stem for fourth fruit branch from the terminal was 49.1%-51.5%, and the position for opened boll from the top was 7.1-8.1, which was the most favorable for the formation of the highest flocculation intensity, that was, the most favorable for centralized flocculation. Therefore, reasonable DPC operation can adjust the mature phase of centralized boll opening of direct-seeding cotton after wheat, and lay a foundation for mechanical harvesting.